The Laser Sight
    The science fiction of the thirties, forties, and fifties was well stocked with death rays. Thi sis about the first thing that enters people minds, when we consider millitary use of the laser, but until recently, this was a false impression. Millitary interest in lasers has centered around their use as target illuminators, rangefinders, and sights. More recently, many armies have taken to the use of laser blinding deviecs called dazzlers, and the United States now has three laser weapons systems of which I am aware, and maybe more which are being kept under wraps. I will not really get any further into the use of lasers in the millitary, because this is a different line fo development than that taken by civilian and police uses.
    As early as the seventies, police agencies began to use laser sights on tactical squad weapons. These were tube based weapons, generally being based around helium neon lasers. They were heavy, somewhat delicate, and obscenly expensive. Most had key locked on off switches, and many featured external battery packs to try and keep the weight of the rifle mounted components managable. These units were, by an unofficial agreement, not marketed to civilians. Most of the early rifle mounted units had laser tubes of up to 15mw, as opposed to the 1 to 5 mw units common in today's laser diode units. Today's best units, the ones designed for rifle use, still use tubes, for a couple of reasons. THe first is that the tubes are readilly available at 15mw power levels. The second is that there is less beam divergance, and mor eefficient use of hte power. Thus, a 5mw tube appears brighter, and has a tigter beam than a 5mw diode. Laser diodes of greater than 5 mw are uncommon, while 15 mw laser tubes are in abundant supply.

IR lasers and night scopes
intenal lasers
laser diode units